The total synthesis of the antitumor agents coriolin and diketocoriolin B is proposed. Two model compounds will also be prepared. The purposes of this research are to develop methodology for the construction of compounds, to define the structure-activity relationship for the coriolins, and to provide compounds for potential chemotherapeutic treatment of cancer. The synthetic routes feature the Diels-Alder reaction of 2-phenylthiocyclopent-2-enone with 1,3-pentadiene to form the BC-ring juncture, and a method for assembling the sensitive diepoxyketone of the A-ring under mild conditions.